Linear-type illumination devices typically are characterized by multiple light sources mounted and spaced apart from one another along a length of an elongate substrate. Such illumination devices are often designed to present a low profile when installed flush to an existing surface, such as a wall.
Current linear illumination device designs commonly consist of multiple members that often are complex to manufacture and assemble. For example, linear illumination device components may include light sources, circuit boards, power supplies, heat sinks, support structures, electrical connectors, external housings, enclosures/reflectors, and inter-member fasteners. Design complexity may negatively impact both the manufacturability and the ease of installation of linear illumination devices.
More specifically, design complexity may complicate volume manufacturing of illumination products, which often involves collaboration between Original Equipment Manufacturers (OEMs) and Value Added Resellers (VARs). As used herein, an OEM is a company whose capital goods are used as components in other companies' finished consumer goods. A VAR is a company that builds and sells a finished consumer good using an OEM's components. The OEM often will customize component designs based on a VAR's requirements. Complexity of design in a component and/or a finished consumer good often results in error-prone and time-consuming assembly processes, and may make separation of distinct product manufacturing responsibilities among OEMs and VARs unworkably difficult.
A major design decision that may significantly impact illumination product cost and complexity is selection of the type of light sources to include in the product. For example, digital lighting technologies such as light-emitting diodes (LEDs) offer significant advantages over legacy light sources such as incandescent and fluorescent lamps. These advantages include, but are not limited to, better lighting quality, longer operating life, and lower energy consumption. Consequently, LED-based lamps increasingly are being used not only in original product designs, but also in products designed to replace legacy light sources in conventional lighting applications such as linear lighting devices. However, a number of design challenges and costs are associated with replacing traditional lamps with LED illumination devices. These design challenges include thermal management, installation ease, and manufacturing cost control.
The complex designs of current LED-based linear illumination devices often suffer from high material and component costs, and also from cumbersome component configurations that may sacrifice lighting adjustability and limit customization options. Design decisions that fix the positions or interrelationships between members of a linear illumination device can compromise the ability of a manufacturer and/or an installer to tailor or reconfigure the device to meet a consumer's lighting performance requirements.
The lighting industry is experiencing advancements in LED applications, some of which may be pertinent to improving the design of linear illumination devices.
U.S. Pat. No. 7,815,341 to Steedy et al. discloses a low-profile strip illumination device having a substrate supporting an elongate heat conductor as well as positively and negatively charged elongate rails. A plurality of LEDs are mounted so as to be powered by the elongate rails, and so as to define a heat flow path from each LED through the elongate heat conductor and to the environment. However, relying on separate components for mechanical support (i.e., the substrate) and for thermal management (i.e., the elongate heat conductor) adds to design complexity for the disclosed device.
U.S. Pat. No. 8,267,540 to Klus discloses a linear lighting apparatus that includes an elongated element having a substantially U-shaped cross section and an LED strip placed longitudinally along a bottom of the elongated element. However, the depth of the U-shape elongated element presumes recessed mounting, thereby precluding low-profile flush-mounting applications. Also, the placement of LEDs on a common strip prevents reconfiguration and/or replacement of subsets of the LEDs employed in the linear lighting apparatus.
U.S. patent application Ser. No. 11/026,816 by Reo et al. discloses a linear lighting apparatus having a plurality of LEDs, a plurality of optical assemblies, and a housing. The apparatus housing is configured to hold a secondary optical assembly and to dissipate radiated energy from the LEDs. However, the depth of the U-shaped housing suffers the same recessed mounting disadvantage as the Klus implementation. Furthermore, delegating primary mechanical support of the optical assemblies to an LED tray while relying on the housing to provide primary thermal management for the optical assemblies results in a component proliferation problem similar to that exhibited by the Steedy implementation.
Accordingly, a need exists for a low-profile, LED-based linear illumination device that is less complex in design, less expensive to manufacture and assemble, reconfigurable during assembly and post-installation, and efficient at heat dissipation.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.